Escape Velocity of virtual particles

  • Thread starter RuroumiKenshin
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Greetings !

Majin,
Schwarzchild was making calculations a few years
after the 1915 publication of GR and came up
with the Schwarzchild Radius which is a radius
at which the curvature of space-time is
so extreme that the escape velocity is larger
than c (and since nothing can go faster than
c - nothing escapes). He sent his solution to
Einstein and thus it was published.

About 40 - 50 years ago as indirect observations
of the cores of galaxies and stars apparently
orbiting "nothing" and powerful radiation
emmissions became considrable, the BHs finally
seemed "real". In the years before that
Schwarzchild's solution just seemed to be a
"weird" result of GR.

About 30 years ago Stephen Hawking had a thought -
if BHs are real then they appear to violate the
second law of Thermodynamics that states that
entropy must always increase. It seemed, at the
time, as though BHs just absorb energy and never
"give it up". Then he considered what will
happen near a BH from the perspective of QM.

QM states that space is not "empty". It is full
of particles of all kind that appear and then
anihilate each other on the microscopic space-time
scales.

However, like damgo and I said before - if you can
create a strong enough field you can prevent these
particles from anhilitaing with each other. So,
Hawking calculated that the amount of energy that
will be "released" to the rest of the Universe
from near the EH accounts precisely(I believe) for
the "requirement" of the second law of Thermodynamics.

Live long and prosper.
 

RuroumiKenshin

Damgo:
Because light doesn't propagate into the shadowing brane, the darkness/unknown matter (aka dark matter) we see is due to this effect. Since only gravitational forces can propagate through the shadowing brane, the abnormal velocities of galaxies is caused by the gravity which influences the galaxies through the other brane. If there's a book store around where you live, you could probably read about it there(if you do, it's in the last chapter).

Drag:
I thought Hawking radiation was the result of quantum fluctuations. I read photons where emitted from the black hole. This is wierd, right? If it is perfectly tenable, then I am induced to conclude that virtual particles are a classification for a variable characteristic for particles (I have yet to discover this variable).
 

drag

Science Advisor
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Greetings MajinVegeta !

First of all I'd like to suggest something if
I may - all this discussion of theories currently
in the proccess of development should be separated
from this discussion. Further more, I think it's a
good idea to have such a separation in general
between accepted theories and incomplete theories
that are possibly wrong or misguiding. The greatest
minds on the planet are working to develop these
theories, so I believe it would be most sensible
not to question them too closely unless/until they
establish themselves as really accepted theories.
(Though prof. Hawking's popular science books can
really spark an amateur's imagination. :wink:)

Now to the subject at hand: Hawking Radiation
particles are NOT virtual particles ! They are
real. The virtual particles we discussed earlier
are quantified fields/interactions. QM does
not have "fields" it quantifies everything including
fields - separates them into individual quanta -
wave-particles.

The particles that are momentarily created near and
outside the EH (and everywhere else in the Universe too)
are real. The difference is that near an EH the
gravitational fields are so powerful that the
"reunion" may be prevented and one of the particles
(or both) is absorbed by the BH.

Hawking radiation particles are not just photons
(EM waves), they can be any particles or anti-particles.

I do not know the likeliness of the creation of
massless particles and photons in particular as
compared to that of particles that do have rest
mass(and thus travel at less than c - light speed),
but clearly the first are sure to escape from the
vecinity of a BH if their counterpart is destroyed
while particles with rest mass will require a lot of
energy to do so. So, photons are the more important
"candidates".

Is it clearer now ?

Live long and prosper.
 
Last edited:

RuroumiKenshin

YES, much clearer. But I still don't comprehend the "existence" of non-real particles.

Can you differentiate the incomplete theories between the complete theories for me?
 

drag

Science Advisor
1,055
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Greetings !
Originally posted by MajinVegeta
But I still don't comprehend the "existence"
of non-real particles.
Try these links (they're not that great really
but unfortunetly they're not easy to find, maybe
someone can post better ones):
http://www.boogieonline.com/seeking/destruction/empty.html
http://www.wikipedia.org/wiki/Virtual_particle
http://www.wikipedia.org/wiki/Quantum_physics
http://shop.store.yahoo.com/scibook/nothingness.html [Broken]
http://users.senet.com.au/~wiblin/science/quantum/question6.html [Broken]
http://www.calphysics.org/zpe.html
http://members.optushome.com.au/aussff/quantumphysics.html [Broken]
Originally posted by MajinVegeta
Can you differentiate the incomplete theories
between the complete theories for me?
QM and GR are mostly complete and accepted theories.
Strings, branes, quantum gravity and others are not, yet.

Live long and prosper.
 
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